Last with detachable heel core

ABSTRACT

A LAST PROVIDED WITH A DETACHABLE HEEL CORE FOR SHOE MOLDING OPERATIONS, THE HEEL CORE BEING CONNECTED TO THE LAST DURING THE MOLDING OPERATION AND AUTOMATICALLY DETACHABLE THEREFROM WHEN THE FINISHED SHOE IS STRIPPED FROM THE LAST TO ALLOW THE LAST TO BE REMOVED AND THEREAFTER TO BE EXTRACTED FROM THE STIPPED SHOE.

J. G. WINKLER 3,619,838

LAST WITH DETACHABLE HEEL CORE 2 Sheets-Sheet 1 Nov. 16, 1971 Filed May 6, 1970 Izzuerzdar $41M Q Wax/Z [er Nov. 16, 1971 Filed May 6, 1970 J. G. WINKLER LAST WITH DETACHABLE HEEL CORE 2 Shoots-Shoat 2 if g a United States Patent 3,619,838 LAST WITH DETACHABLE HEEL CORE Julius G. Winkler, Lexington, Mass., assignor to Compo Industries, Inc., Waltham, Mass. Filed May 6, 1970, Ser. No. 35,144 Int. Cl. A43d 3/00 U.S. Cl. 12-135 Claims ABSTRACT OF THE DISCLOSURE A last provided with a detachable heel core for shoe molding operations, the heel core being connected to the last during the molding operation and automatically detachable therefrom when the finished shoe is stripped from the last to allow the last to be removed and thereafter to be extracted from the stripped shoe.

BACKGROUND OF THE INVENTION Heel cores attached to lasts are not new, the purpose being to lighten the shoe by providing in the heel a plurality of holes or voids from top to near the bottom thereby reducing the overall weight of rubber or plastic of Which the heel is comprised. For fiattees and openback structures the fixed core presents no special problem but for high heel shoes and closed back shoes which pose some difficulties in removing the last even though the latter is constructed to enable foreshortening it, the addition of the high heel makes it impossible to strip the shoe without damage thereto. While employing lasts which can be foreshortened helps, it is still desirable to avoid having to bend the back part of the shoe relative to the forepart to effect stripping because such bending if excessive forms marks in the finish. The purpose of this invention is to provide for employing a removable heel core thus to enable lightening the heel structure without the attendant difliculties of stripping and excessive bending of the shoe which at this period of its manufacture when the bottom material is still somewhat tender it may separate from the upper.

SUMMARY As herein illustrated, the invention resides in the combination with a last of a releasably attached heel core which is adapted to be held in place at the bottom of a last while the molding operation is in process but which is adapted to be detached from the bottom of the last by pulling away from the bottom of the last during stripping and from the bottom of the shoe following stripping. The aforesaid heel core may be employed advantageously with both solid lasts and split lasts. Specifically, the bottom of the last at the heel end is recessed to receive the heel core and there are mutually engageable releasable locking means interengageable by inserting the heel core into the recess to hold the heel core in place and disengageable by pulling the heel core away from the bottom. The interengageable means may be magnetized parts on the last and heel core or a spring-pressed ball and detent. The heel core has a base adapted to fit into the recess and optionally an eye at its inner side by means of which a hook may be employed after the shoe is stripped to extract the heel core from the heel end of the shoe. Alternatively, a chain may be attached at its opposite ends, respectively, the base of the heel core and to the bottom of the recess. The heel core has a plurality of core rods extending from it and the outer ones of the core rods are preferably spaced from the edge of the base to provide a shoulder at their junction with the base over which the upper is adapted to be lasted. The shoulder assists in holding the heel core in place during the mold- 3,619,838 Patented Nov. 16, 1971 ing operation by constriction of the lasting margin thereabout.

The invention will now be described with reference to the accompanying drawings wherein:

FIG. 1 is an elevation of a two-part last in which the heel part is movable relative to the forepart to effect foreshortening, showing the heel core attached to the heel part;

FIG. 2 is a top view of FIG. 1;

FIG. 3 is a fragmentary elevation of the last shown in FIGS. 1 and 2 with a shoe on the last showing the shoe partly stripped from the last;

FIG. 4 is a fragmentary transverse section of the heel end of the last with the heel core attached thereto by a spring-pressed ball;

FIG. 5 is a view, partly in section, of the heel core removed from the last;

FIG. 6 is an elevation taken from the right side of FIG. 5;

FIG. 7 is a plan view of FIG. 5;

FIG. 8 is a fragmentary transverse section of the heel end of the last with the heel core attached thereto by magnetic means; and

FIG. 9 is a fragmentary transverse section of the heel end of the last with the heel core connected to the last by an extensible element.

The invention, as herein illustrated, comprises essentially the combination with a last of a removable heel core, and although illustrated herein in conjunction with a twopart last, it is adapted to be used in combination with a one-piece last.

As illustrated, the heel core 10 is mounted in the bottom of the last at the heel end as shown in FIGS. 1 to 4, inclusive, in a recess 12 formed in the bottom. The heel core (FIGS. 5 and 6) comprises a base 14 which corresponds in configuration to the heel end of the last but is smaller, as shown in FIG. 2, and has fixed to one side a plurality of core rods 16 which extend perpendicularly from said side, the core rods being arranged symmetrically with respect to the median line of the base and comprising three rods at each side of the median line. The ends of the rods attached to the base are set inwardly from the peripheral edge thereof so as to provide a shoulder 18 marginally of the base. The core rods 16 taper from the ends attached to the base toward their distal ends and preferably are comprised of a material which may be treated to have a smooth surface.

In one form, the base 14 of the heel core is provided at its opposite side with a pin 20 containing a transverse threaded opening 22 into which there is screwed a metal plug 24. The metal plug 24 contains in one end a recess 26. A hole 28 extends transversely through the pin 20 and the plug 24.

The heel end of the last, whether a one-piece last or a two-piece last, has at the bottom of the recess 12 a hole 30 and the base 14 of the heel core and the pin 20 are dimensioned to fit into the recess 12 and the hole 30 in the last. The heel core, as shown in FIG. 4, is retained in the last by a spring-pressed ball 32 disposed in a transverse opening 34 in the last, one end of which is in communication with the hole 30 and the other with one side of the last. A coiled spring 36 is held against the ball 32 by a set screw 38. The end of the transverse opening 34 entering the hole 30 is smaller in diameter than the ball.

In use for molding operations, the heel core 10 is inserted into the recess 12 to engage the pin 20 within the hole 30 and the ball 32 with the recess 26 whereupon the upper U, to which a bottom is to be attached by the molding process, is drawn onto the last, preferably by stringlasting, as shown in FIG. 2, to constrict the lasting margin m about the last and over the marginal edge of the bottom of the last. Constriction of the upper draws the lasting margin inwardly about the shoulder 18, thus assisting in holding the heel core in place. The mold with the upper lasted thereto is now moved into engagement with an open top mold and the bottom, including the heel, formed against the bottom of the last and about the heel core. Following application of the bottom to the upper the heel end of the finished shoe is pushed upwardly in the case of a one-piece last relative to the forepart by grasping the heel end of the shoe and pushing upwardly, as shown in FIG. 3. There is suflicient frictional engagement between the core rods with the heel so that the upward movement disengages the base of the heel core from the last thus allowing the shoe to be easily stripped from the last with out excessive bending between the heel end and forepart of the shoe. After the shoe is stripped from the last, the heel core is removed from inside the shoe by inserting. a hook or similar implement through the hole 28 in the heel core and pulling it out of the shoe. For very deep, that is high heels, it may be desirable to use a split last as shown in FIGS. 1, 2 and 3, in which the heel end 40 of the last is movable relative to the forepart 42. Two-part lasts of this kind are conventional and in this particular instance the two parts are held in their extended position by a spring-pressed pin 44 which may be retracted by means of a button 46 to permit the parts to be moved relative to each other to effect foreshortening. Foreshortening is limited by a stop pin 48 to substantially the dotted line position shown in FIG. 1. As described heretofore with respect to the one-part last, the heel core is removably set into a recess 12 in the bottom of the heel part 40;

The heel core described above is mechanically held in place by the spring-pressed ball 32. Optionally, however, it may be held in place by magnetic means as shown, for example, in FIG. 8, by setting magnetic blocks 50-50 into the last at opposite sides of the hole 30 and providing a plug 24 of a magnetizable material so that it will be held in place by the magnets.

To avoid the necessity of having a separate implement or tool for removing the heel core and also to eliminate misplacement of a heel core, the latter may be detachably but permanently connected to the last with which it is used as shown in FIG. 9, by means of a flexible connector 52 in the form of a chain. In this form the bottom of the last contains a chamber 30a at the bottom of the recess 12 for receiving the chain 52. One end of the chain is connected to the last by a screw eye 54 screwed into the bottom of the chamber 30a and the other end is connected by a ring 56 to the pin 20 on the base 14. By providing a close fit between the base 14 and the recess 12 and relying upon constriction of the lasting margin about the shoulder 18, the heel core can be held in place during the molding operation without necessarily employing a spring-pressed ball or the magnetic means previously described. When the shoe is stripped from the last the heel core will be removed from the bottom of the last with the shoe. After the shoe is stripped, the heel core may be extracted from inside the shoe by using the last itself as a handle for pulling the end of the chain attached to it.

The heel core may be comprised of any suitable material, for example, aluminum, the surface of which may be polished to make it smooth and substantially frictionless and if desired a parting compound of the kind used in molding processes may be applied to the core rods to facilitate disengaging the core rods from the formed heel. The number and length of the core rods will, of course, depend upon the size of the heel and the depth of the heel.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents falling within the scope of the appended claims.

I claim:

1. The combination with a last, of a heel core about which the heel is formed in a mold, characterized by means detachably mounting said heel core to the heel end of the last for removal with the completed shoe when the latter is stripped from the last.

2. The combination according to claim 1, wherein the bottom at the heel end of the last contains a hole and the heel core embodies a pin interengageable with the hole, and there is means releasably holding the pin and hole interengaged.

3. The combination according to claim 2, wherein said last means is a spring-pressed ball.

4. The combination according to claim 2, wherein said last-named means comprises magnets and the pin embodies a magnetizable insert.

5. The combination according to claim 2, wherein the heel core has a base from which said pin extends, the bottom at the heel end of the last contains a recess shaped to receive said base, and the hole for receiving said pin is at the bottom of the recess.

6. The combination according to claim 1, wherein the last comprises a forepart and heel part, said parts being mutually interengaged for relative movement from a position of alignment to positions oifset such as to foreshorten the last from tip to heel, and said hee] core is detachably mounted in the bottom at the heel end of the heel part.

7. The combination according to claim 1, wherein the bottom of the last at the heel end contains a recess and the heel core comprises a base adapted to fit into the recess in the bottom of the last, and a plurality of core rods ertending therefrom in a direction away from the bottom of the last.

8. The combination according to claim 7, wherein there is a shoulder at the junction of the core rods with the base over which the upper is adapted to be lasted when mounted on the last preparatory to the molding operation.

9. Apparatus according to claim 8, wherein the heel core embodies an eye at its inner end and the bottom of the last a hole for receiving the eye when the heel core is mounted on the heel end, said eye being adapted to receive a hook by means of which the heel core may be ertracted from the finished shoe.

10. The combination according to claim 1, wherein the heel core comprises a base from which extend one or more core rods, the heel part of the last contains a recess inwardly of its bottom for receiving the base, and a chamber inwardly of the recess, and there is a chain disposed in said chamber with one end anchored to the heel part at the bottom of the chamber and the other end to the base of the heel core by means of which the heel core is permitted to be detached and separated from the last when the shoe is stripped from the last and by means of which the heel core may be extracted from the stripped shoe after the last has been removed therefrom.

References Cited UNITED STATES PATENTS 3,203,050 8/1965 Hoffman l2l35 R 1,705,222 3/1929 Kenney 12-435 A 3,317,940 5/1967 Ludwig l'2l35 R PATRICK D. LAWSON, Primary Examiner 

